Agent says he's never violated that policy in the four years he has worked for DART. He has never touched a passenger beyond securing a wheelchair, much less had sexual contact with one, he says.

"I've been following [the policy] for four years. You look at my file I've got nothing but compliments."

After the alleged incident, Agent says he gave DART police a cheek swab so his DNA could be tested. He assumes the police have cleared him because he was subsequently allowed to return to work.

Earlier Tuesday, DART spokesman Morgan Lyons told The Dallas Morning News that the vehicle Agent was driving had a camera on it. He has since, according to the News, retracted that statement.

Update: 2:37 p.m.:DART spokesman Morgan Lyons gave us the following statement: "DART Police and other agencies investigated the allegations when they were made in September 2013. Investigative results could not confirm the allegations. DART has no further comment on the civil lawsuit filed today relating to the September 2013 claim."